No two relationships are the same.
My children fight something chronic. Honestly, most people who know us and love us cannot quite believe how much they fight. It's the hardest thing.
I read 'siblings without rivalry', and although i wasn't really pitting them against each other I did have the misguided belief that they should 'get on' and be friends.
But now I know that whilst that sounds like a lovely fairy tale, the truth is, they don't. They don't have to like each other or be friends. They just have to learn to tolerate each other and live together and hopefully be kind and love each other eventually. My job is no longer trying to make them play together and enjoy each other's company. When they want to play together they do, and when one of them doesn't, then I help them to separate.

They can be wonderful, don't get me wrong. But they can be unbelievable awful to one another.

I know of siblings both boys, similar in age to mine, and they never fight. The eldest is so tolerant and gives in to his younger brother all the time for the sake of peace. He is a peaceful soul. So, that's their dynamic. I am envious of the peace - but I am resigned in the knowledge that it's not ever going to be the way my boys relate to each other.

If we go to a park together, they will play together for a bit, then usually find their own thing to do. Sometimes when we are at home if dS1 has an idea they will work on it together I.e. Building ramps for their cars/trucks, making cushion cubbies, etc. but it is usually DS1s idea and he is leading the show, and then often at the end ds2 will do 'something wrong' and they start scrapping.

It's been like this since I can remember. Ds1 is six and is now at school. I thought they'd be different now, but they are still just the same little people, they just spend less time together.

Would you like to read siblings without rivalry? I can send it to you. I don't presume that it will help you mould their relationship, but it might help you understand it a bit more. And certainly know that you are not alone. We all want our kids to be best mates.